JPS5769913A - Input buffer circuit for measuring device - Google Patents

Input buffer circuit for measuring device

Info

Publication number
JPS5769913A
JPS5769913A JP55146482A JP14648280A JPS5769913A JP S5769913 A JPS5769913 A JP S5769913A JP 55146482 A JP55146482 A JP 55146482A JP 14648280 A JP14648280 A JP 14648280A JP S5769913 A JPS5769913 A JP S5769913A
Authority
JP
Japan
Prior art keywords
input
power supply
fet16
lowering
buffer amplifier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP55146482A
Other languages
Japanese (ja)
Other versions
JPS641972B2 (en
Inventor
Akira Taniguchi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP55146482A priority Critical patent/JPS5769913A/en
Publication of JPS5769913A publication Critical patent/JPS5769913A/en
Publication of JPS641972B2 publication Critical patent/JPS641972B2/ja
Granted legal-status Critical Current

Links

Abstract

PURPOSE: To prevent the lowering in impedance due to power supply interruption surely, by providing a photocoupling element at the input of a buffer amplifier, inserting a photodetector in series with it, connecting the light emitting element to the power supply and avoiding the limit of input range.
CONSTITUTION: A photodetector FET16 of a photocoupling element 14 is inserted between the + input terminal of an input buffer amplifier 11 and an input terminal 15 of a buffer circuit, and a power supply voltage Vcc is given to a light emitting element 17 via a resistor 18. The FET16 is at a low resistance through the light emission of the element 17 during the application of power supply voltage, and when the power supply is interrupted, the FET16 is at high resistance to compensate the lowering in the input impedance of the buffer amplifier. With this constitution, the input voltage range of a measuring unit, especially a limit is unnecessary, and the lowering in the input impedance of the measuring unit can be prevented at the interruption of power supply surely.
COPYRIGHT: (C)1982,JPO&Japio
JP55146482A 1980-10-20 1980-10-20 Input buffer circuit for measuring device Granted JPS5769913A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55146482A JPS5769913A (en) 1980-10-20 1980-10-20 Input buffer circuit for measuring device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55146482A JPS5769913A (en) 1980-10-20 1980-10-20 Input buffer circuit for measuring device

Publications (2)

Publication Number Publication Date
JPS5769913A true JPS5769913A (en) 1982-04-30
JPS641972B2 JPS641972B2 (en) 1989-01-13

Family

ID=15408631

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55146482A Granted JPS5769913A (en) 1980-10-20 1980-10-20 Input buffer circuit for measuring device

Country Status (1)

Country Link
JP (1) JPS5769913A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54107250A (en) * 1978-02-10 1979-08-22 Hitachi Ltd Signal transfer circuit using photo coupler
JPS5564158A (en) * 1978-11-01 1980-05-14 Nippon Denso Co Ltd Ignition distributor
JPS5587717A (en) * 1978-12-05 1980-07-02 Haessle Ab Cardiotonic glycoside containing medicine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54107250A (en) * 1978-02-10 1979-08-22 Hitachi Ltd Signal transfer circuit using photo coupler
JPS5564158A (en) * 1978-11-01 1980-05-14 Nippon Denso Co Ltd Ignition distributor
JPS5587717A (en) * 1978-12-05 1980-07-02 Haessle Ab Cardiotonic glycoside containing medicine

Also Published As

Publication number Publication date
JPS641972B2 (en) 1989-01-13

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